Keep particles from fluid simulation in render?
You can sort of do that, using the viewport render:

1) Disable all overlays and set the view mode to rendered:



2) In the domain's material settings panel, set the Blend Mode to Alpha blend and make sure Show Backface is checked:



3) Change the domain's material to Transparent BSDF:



4) If you don't want to see the viewport's background, check the transparent option in the render tab, Film panel:



5) In the viewport, go to the View menu, and make a viewport render:



And here's the result:



You can use this in compositing if you need it to see it in your full feature render. Though I can't think of a way to make it look not overlayed on top or bellow.